In a known electrowetting element, walls surround a display area and at least partly confine an oil based liquid from overspilling into an adjacent electrowetting element. Such a wall is formed of a material transmissive to visible light. Metallic parts underlying the wall may therefore reflect light, having passed through the wall, back out through the wall and towards a viewer. This can negatively affect the contrast of an image displayed by an array of such electrowetting elements. Accordingly, it is desirable to improve the contrast performance of an electrowetting element.